One-time CRISPR therapy keeps cholesterol lower for a full year in early trial

Overview

Updated Sep 3

A single infusion of a CRISPR gene-editing therapy kept LDL cholesterol about 52% lower and triglycerides about 48% lower for a full year. The results, from a 15-patient trial, are the longest durability data yet for in vivo CRISPR in heart disease. They were presented at the European Society of Cardiology meeting and published in the New England Journal of Medicine.

CTX310, from CRISPR Therapeutics, switches off the ANGPTL3 gene in liver cells, mimicking a rare genetic state that protects against heart disease. No treatment-related serious adverse events occurred in the first year, though one participant with advanced cardiovascular disease died six months after the lowest dose. If the effect holds in larger trials, a single infusion could replace daily statins for the many patients who stop taking them.

Why it matters

If the effect holds in larger trials, a single infusion could replace daily statins for millions of patients.

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Key Indicators

52.5%

LDL cholesterol reduction at 12 months

Mean reduction from baseline at the highest dose in the Phase 1a trial.

47.8%

Triglyceride reduction at 12 months

Mean reduction from baseline at the highest dose.

79%

ANGPTL3 protein reduction

Mean reduction at the highest dose, with a maximum of 89%.

Patients in Phase 1a trial

All completed at least one year of follow-up.

15 years

Planned safety follow-up

FDA-recommended long-term monitoring for gene-editing therapy recipients.

Voices

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People Involved

Luke Laffin, M.D.

Cleveland Clinic cardiologist and first author of the CTX310 trial

Leading the CTX310 clinical program at Cleveland Clinic

Steven Nissen, M.D.

Cleveland Clinic cardiologist and senior investigator on the CTX310 trial

Senior investigator on the CTX310 program

Organizations Involved

CRISPR Therapeutics

Biotechnology company

Developer of CTX310, presenting Phase 1a data

The company developing CTX310, an in vivo CRISPR-Cas9 therapy targeting ANGPTL3.

Cleveland Clinic

Academic medical center

Conducted the Phase 1a trial

The hospital system that ran the first-in-human trial of CTX310.

Timeline

November 2025 September 2026

3 events Latest: September 1st, 2026 · 1 week ago

September 2026
Results reach wider public audience
Latest Media

Human Progress publishes an alert on the yearlong cholesterol reduction results.
September 1st, 2026
August 2026
One-year durability data presented at ESC Congress
Clinical Data

NEJM-published results show LDL down 52.5% and triglycerides down 47.8% at 12 months.
August 28th, 2026
November 2025
Initial CTX310 data shows two-month lipid drops
Clinical Data

Early Phase 1a results show CTX310 lowers LDL and triglycerides at two months.
November 2025

Scenarios

Phase 1b confirms fixed-dose results

Likely Resolves by End of 2026

Discussed by: CRISPR Therapeutics, which said it expects to share Phase 1b data in the second half of 2026

The Phase 1b trial tests a fixed flat dose equivalent to the most effective Phase 1a dose (0.8 mg/kg) in patients with severe hypertriglyceridemia. Similar LDL and triglyceride reductions with a clean safety profile would give the program a reproducible dosing regimen and a path to larger trials.

CTX310 advances to a pivotal trial

Possible Resolves by End of 2027

Discussed by: Cleveland Clinic investigators, who say the therapy could eventually give patients a choice between daily pills and a one-time infusion

A larger Phase 2 or Phase 3 trial would be needed to support FDA approval. The open questions are whether the effect persists beyond one year and whether the safety profile holds in a broader, more diverse population than the 15-patient Phase 1a.

Extended follow-up reports a treatment-related serious adverse event

Unlikely Resolves by End of 2027

Discussed by: Safety monitors and regulators; the FDA has recommended 15 years of follow-up for all gene-editing therapies

The one-year data showed no treatment-related serious adverse events, but the follow-up window is long. One participant died six months after infusion from advanced cardiovascular disease at the lowest dose, and one had a transient liver enzyme elevation. Permanent ANGPTL3 editing could in principle have effects that take years to appear.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

2003-2015

PCSK9 discovery to drug approval (2003-2015)

In 2003, researchers found that people with loss-of-function mutations in the PCSK9 gene had very low LDL cholesterol and low rates of heart disease. That genetic insight led to injectable antibody drugs approved in 2015 that block PCSK9 and lower LDL by about 60%.

Then

The drugs became major sellers but require injections every two to four weeks for life.

Now

They validated using human genetics to find cholesterol targets, the same path that led to ANGPTL3.

Why this matters now

CTX310 uses the same genetics-first logic as PCSK9 inhibitors but aims to make the effect permanent with one infusion.

2017

ANGPTL3 human genetics validation (2017)

A 2017 New England Journal of Medicine study of nearly 60,000 people found that carriers of ANGPTL3 loss-of-function mutations had lower LDL, lower triglycerides, and 34% lower odds of coronary artery disease, with no apparent health downsides.

Then

The study made ANGPTL3 a validated drug target and prompted development of antibody and gene-silencing approaches.

Now

It provided the natural experiment that CTX310 aims to replicate permanently.

Why this matters now

CTX310 is an attempt to convert any patient into a lifelong ANGPTL3 loss-of-function carrier.

November 2022

Hemgenix approval (2022)

The FDA approved Hemgenix (etranacogene dezaparvovec) in 2022 as the first one-time gene therapy for hemophilia B, delivered as a single infusion that lets patients produce clotting factor themselves.

Then

The therapy freed patients from regular factor infusions, at a cost of millions per dose.

Now

It established the regulatory and manufacturing precedent for one-time in vivo gene therapies.

Why this matters now

CTX310 follows the same one-time in vivo model but targets a common condition affecting millions, not a rare disease affecting thousands.